DOE-HDBK-1015/2-93Hazards of Chemicals and GasesFLAMMABLE AND COMBUSTIBLE LIQUIDSRev. 0CH-05Page 4114 F rise in temperature. Outage space for gasoline of two percent of the capacity of the tankor compartment is recommended, and permanent high-level markings should be installed.Storage tanks should be provided with vents. Vent pipes of underground tanks storing Class Iflammable liquids should terminate outside buildings, higher than the fill pipe opening, and notless than 12 feet above the adjacent ground level. They should discharge vertically upward, andbe located so that flammable vapors cannot enter building openings or be trapped under eavesor other obstructions. Vent pipes from underground tanks storing Class II or Class III liquidsshould terminate outside buildings and higher than the fill pipe opening. Vent outlets should beabove normal snow level.Additional information concerning installation, protection, and spacing of storage tanks locatedabove ground, underground, or in areas subject to flooding is beyond the scope of this course.If this information is desired, it may be found in the National Fire Protection AssociationStandards.Flammable or combustible liquids in sealed containers represent a potential hazard rather thanan active hazard -- the possibility of fire from without. By the same reasoning, inside storagerooms are undesirable. If they must be used, they should be isolated as much as possible, andlocated at or above ground level. They should not be located over basements and shouldpreferably be along an exterior wall.Every inside storage room shall be provided with either a gravity (low level intake) or acontinuous mechanical exhaust ventilation system. Mechanical ventilation must be used ifClass I liquids are contained or dispensed inside the room.Storage cabinets have specific limits on the amount and class of flammable or combustible liquidsthat may be stored in them. They must be constructed and sealed so as to be fire resistant.Cabinets shall be labeled conspicuously -- FLAMMABLE-KEEP FIRE AWAY.The most advisable storage facility is a separate building set some distance from normallyoccupied plant areas. The construction can be similar to that specified for inside storage rooms.The types and classes of flammable and combustible liquids stored will determine the best designto be used.